This invention relates to a time-keeping apparatus which includes an electronically regulated indicating system. The invention relates to a time-keeping apparatus, in particular a wrist watch which contains a quartz oscillator and electronic frequency dividers, as well as an electronically regulated mechanical time-keeping system which is part of an indicating system.
Quartz wrist watches are known which contain a quartz oscillator in combination with a frequency divider and an electro-mechanical indicating system controlled directly by the output pulses of the frequency divider.
Particular disadvantages of known quartz time-keeping systems, especially quartz wrist watches, consist in that the mechanical indicating system of such watches requires a relatively high power input in order to achieve a high stepping reliability; this power input can be reduced only if a greater sensitivity is permitted. The high sensitivity results in the system or watch becoming undesirably responsive to disturbances. Furthermore, in known systems which employ directly controlled stepping motors or directly synchronized oscillating systems and conventional motors, a design is necessary which must correct or reverse possible errors within a single stepping period. In such systems, the sensitivity to shocks, for example, during a wearer's exercise in sports, can result in a permanent deviation of the setting.
In order to avoid these disadvantages substantially, it has heretofore been necessary to provide expensive special devices for the indication and stepping system; for example, oscillating systems having high energy content, i.e. having large amplitudes and high frequencies.
As experiments and practical results of utility quartz watches, especially of wrist watches, have shown, these difficulties occur in principle in all previously employed versions of electro-mechanical drive means for indication systems, whether they are tuning fork, leaf spring or balance wheel systems, synchronous motors, synchronized motors, directly synchronized oscillating systems, stepping motors or electro-mechanical stepping mechanisms. Attempts have been made, therefore, to install blocking devices in stepping systems in order to prevent an undesired stepping due to disturbances, for example, mechanical shocks and the like. However, these blocking devices are also subject to disturbances if an external mechanical disturbing pulse occurs during the stepping process.
In watches employing balance wheel oscillating systems having a frequency of 2.5 Hz, shaking motions and rotational shocks as can occur during rapid hand motions in sports activities or in a vehicle, result in errors, caused primarily by contact chatter, corresponding to a setting difference of several seconds within the time span of one minute. It is for this reason that a low-frequency balance wheel of the frequency usual for wrist watches cannot be directly synchronized with the required reliability.
In other known systems, setting or arrest instrumentalities are used which require supplementary electromechanical transducers. These known systems sometimes have a relatively high energy requirement.